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Letters Patent No. 80,822, dated August 11, 1868. Y

IMPROVEMENT IN ARTIFICIAL TETTE.

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TO ALL WHOM IT MAY OONCERN:

Be it known that I, JETIIRO J. GRIFFITH, oi' Philadelphia, Pennsylvania,have invented anew and useful Improvement'in the Process of MouldingArtificial Teeth; and I do hereby declare thatthe followingsa--full andexact description of the same, reference being had .to the annexeddrawings, forming part hereof, and to the letters of reference markedthereon.

My invention consists of a process whereby the pins commonly employedfor fastening artificial teeth to their vulcanite base are secured tothe teeth with more expedition and less cost than by any processhitherto practised.

In the drawings- Figure 1 is a perspective view of the lower half of anordinary artificial-tooth mould altered to' suit my process, andrepresented as partially lled with the plastic mineral substance of'which the teeth are composed.

Figure 2 is a transverse vertical section of the lsarneon the line z xof iig. 1. I

Figure 3 is a longitudinal vertical section of the same on the line yyof fig. l. i

Figure 4 is a longitudinal section of a tooth, showing the'above-mentioned pin in its proper position,'viz, with oneof its endsembedded in the body ofthe tooth, and its other end projecting.

The half of the mould represented has the ordinary depressions a, iigs.l, 2, and 3, to form the backs of the teeth. I provide this part of themould with the holes c, which are cylindrical, and of about one-half thelength of the pins fin depth, and about equal in diameter to thediameter of a pin-head.

I first partially ll the depressionsia with the mineral substance whichis caused to form a shoulder near the holes c, as shown in figs. 1 and2. Tile pins b are then inserted in the holes c, as shown in figs. 2 and3, the projecting ends of the pins being in contact with the mineral, d,and thus' receiving support suflicient to keep the pins upright. After ashort interval, the filling of depressions a ywith the mineralVsubstanceis completed, the half of the mould not represented is filled,land the other operations necessary to finish the teeth are thenperformed in the ordinary manner. l i

Having thus described my invention, I claim, and desire to secure byLetters Patente- The above-described mode of effecting the attachment ofpins to artificial teeth in the process of moulding.

.IETIIRO J. GRIFFITH.

Witnesses: Y

Guo. E. BUCK'LEY, W. A. A. McKINLEY.

